Automatic electric switch.



UNITED STATES Patented October 25, 1904.

PATENT OEEICE.

JAMES I. AYER, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO SIMPLEX ELECTRIC HEATING COMPANY, OE BOSTON, MASSACHUSETTS, A COR- PORATION OF MASSACHUSETTS.

AUTOMATIC ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 773,182, dated October 25, 1904.

Application flled June 27, 1904. Serial No. 214,231. (No model.)

T @ZZ whom, t may concern.-

Be it known that I, JAMES I. AYER, a citizen of the United States, residing at Cambridge, Massachusetts, have invented Improvements in Automatic Electrical Switches, of which the following description, in connection with the accompanying' drawing, is a specification, like letters on the drawing representing like parts.

This invention relates to an electric switch IO for opening and closing an electric circuit and for means for operating the said switch governed by the condition of a translating device within the circuit.

The nature and extent of the invention will I5 best be set forth in the annexed claims.

Aspecific form of the invention is shown in this application to consist of an electric switch for opening and closing the circuit operated by solenoid-magnets, which in turn 2O are energized by auxiliary or shunt circuits controlled by a thermostat governed by the caloric condition of an electric furnace located in the main circuit; but it will be obvious that the invention is not limited to these particular devices.

The drawing illustrates a switch and a thermostat, somewhat in detail, and the wiring and circuits and electric furnace diagrammatically.

The single figure of the drawing shows diagrammatically an electric furnace A, a thermostat B, partially in cross-section, the electric switch C, partially in cross-section, and also the various connecting-wires and parts.

The particular devices in which I have embodied one form of my invention as illustrative of its general principles are as shown in the accompanying drawing. A suitable generator G has leading therefrom two main wires of the circuit H.

The translating device is herein shown in the form of an electric furnace, two tubes of which, A, are illustrated with a main circuitwire H running to each tube and the circuit comple/ted through the tubes by a connectingwire H The switch proper consists of a pivoted arm D and two pairs of contacts E E, arranged, as shown, one above the other, so that the switcharm in its lowermost position engages the contacts E and in its uppermost position the contacts E.

The switch-arm D is pivoted on a support K, suitably insulated from the framework and provided with a binding-post L for connection with one of the circuit-wires H. The pair of contacts E are also suitably insulated from the framework and provided with a binding-post E, to which is connected one of the main circuit-wires H, and the pair of contacts F are also suitably insulated from the framework and provided with a binding-post F. It will thus be seen that when the switcl arm D is in its lowermost position between the contacts E the main circuit is closed through the generator and translating device, the current passing from the generator G through the lower wire H, through the lower furnace-tube A, through the connecting-wire H', through the upper furnace tubes A, through the wire H, through the binding-post E, through the switch-arm D and bindingpost L, through the wire H back to the generator. 7 5

The switch-arm D is shown as operated by a pair of solenoid-magnets M M', the cores of which are pivoted to the switch-arm at m m/ on opposite sides of its pivotal point. The cores are shown connected with the switch- 8O arm D by links of insulating material m2.

Located on a suitable frame O and each suitably insulated from the said frame O and from each other are three binding-posts l? R S. A branch of the main circuit-wire H runs to the 8 5 binding-post P. The winding of the solenoid-magnet M' is connected at one end with the binding-post E' and its opposite end with the binding-post R. The winding of the magnet M is connected at one end with thc binding-post E and its other end with the binding-post S. 1t will be seen, therefore, that if the switch-arm D is in its uppermost position in engagement with the contacts E if connection is made between the bimling-post P and the binding-post S an auxiliary or shunt circuit will be completed, which will energize the magnet M. NV hen the mag'net M is energized, the switch-arm D will be swung downwardly, breaking' the auxiliary or shunt circuit and cutting out the magnet M, but closing the main circuit throug'h the generator and translating' device. 1t will further be seen that if the switch-arm D is in its lowermost position in engagement with the contacts E if connection is made between the binding-post P and the binding-post R an auxiliary or shunt circuit will be completed, which will energize the mag'net Ml. Vhen the mag'- net M' is energized, the switch-arm D will be swung upwardly, breaking the auxiliary or shunt circuit and cutting out the magnet M and at the same time opening' the main circuit containing` the generator and translating' device, thus cutting' out the translating device.

The means for connecting the binding-posts P and S or P and R to form the desired auxiliary or shunt circuit and energize the desired magnet may be various, according' to the particular conditions and to the particular form which the translating device or current-consumer may take.

Herein I have shown as a translating' device an electric furnace comprising' the tubes A A and a thermostat B as the means for connecting' the binding-posts and forming the auxiliary or shunt circuits. The caloric condition of the electric furnace serves, of course, to operate the thermostat. The thermostat is shown as comprising` a cast-iron slotted tube T, and the frame O is for convenience firmly fastened to this tube. To the base of this slotted tubeT is fastened a brass core or stem U, the opposite end of which projects through the opening' in the tubeT and frame O. The relative expansion and contraction of the iron tube T and the brass core U cause the end of the core U to project more or less, according' to the temperature of the furnace beyond the frame O.

The spring contact-finger a is connected to the binding-post S, and its position is regulated by a set-screws. A contact-point, herein shown as an adjustable set-screw fr, is connected with the binding-post R. A resilient spring' contact-finger p is connected with the binding-post P and projects from the end of the brass core U and in between the contactpoints .s and r. It will thus be seen that when the brass core U lengthens out under increase of temperature it will be brought into contact with the contact-point y', whereby7 connection is made between the binding-post P and the bindingpost R. Then the brass core U retreats upon the cooling of the furnace, the contact-linger j) will be brought into contact with the contact-linger s, forming a connection between the binding-post P and the binding-post S.

The adjustment of the set-screw .v/ and the contact-points fr serves to determine the conditions under which the connection of the binding-posts P and S or P and R, and consequentlythe respective auxiliary or shunt circuits, shall be formed.

It will thus be seen that in the operation of the device illustrated a predetermined condition of the translating' device is made to cause the automatic operation of the switch either to open or close the main circuit, and in this way the condition of the translating' device can be kept within predetermined limits.

More specifically and with the specific devices herein illustrated and with the switcharm in engagement with the contacts E it will be seen that when the furnace is cold the brass core U will be retracted and the contacts p .v in contact required to form the auxiliaryor shunt circuit through the magnet M. If new the current be turned on through the generator, it will pass through the furnace and also through the auxiliary or shunt circuit, energizing the magnet M; but immediately the current passes to the ltranslating device the thermostat acts to separate the contacts s p, and the magnet M and the auxiliary or shunt circuit is broken, cutting' out the magnet M.

1f the circuit-arm Dshould be in its uppermost position in engagement with the contact F when the current is turned ofi' and the furnace cold, when the current is turned on it would pass through the same auxiliary or shunt circuit, energizing the magnet, causing the switch-arm D to swing' into its lowermost position in engagement with the contact E, thus closing the lower circuit and causing the current to pass through the translating' device. It would then immediately affect the thermostat and cause the breaking' of theauxiliary or shunt circuit and the cutting' ont of the magnet M.

"If during the operation of the furnace the heat increases to a predetermined point, the thermostat will cause the contacts y) and 1^ to come together, thus forming' the second auxiliary or shunt circuit and energizing the magnet Ml. This causes the switch-arm D to swing' into its uppermost position, opening' the main circuit and cutting' out the translating device and at the same time breaking' the auxiliary or shunt circuit and cutting' out the magnet M.

It will thus be seen that the action of the switch is in any event positive, that it permits currents ofconsiderable capacity to be interrupted without the risk of serious arcing at the contacts, and that very powerful magnets may be provided to insure the quick make and break action of the switch arm. The fact that each mag'net immediately upon the performance of its function of moving' the switch-arm automatically cuts itself out of circuit makes the operation of the automatic lIO TIS

switch operative at an infinitesimal cost, although at the same time it insures a positive opening and closing of the main circuit.

While I have shown a furnace as the translating device and a thermostat as the active means for causing the operation of the switch, my invention is broader and comprises any other form of translating device or currentconsumer and any other form of device for effecting the operation of the switch which is controlled by predetermined conditions of the translating device or current-consumer.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s-

l. An electric circuit containing a translating device and a switch for opening and closing said circuit, a pair of magnets for respectively causing' the opening and closing movements of said switch, a regulating device controlled by the condition of the translatingdevice and operating under predetermined conditions to eifect the energization of one or the other of said magnets.

2. An electric circuit containing a translating device and a switch for opening and closing said circuit, a pair of magnets for respectively causing the opening and closing' movements of said switch, a reg'ulating' device controlled by the condition of the translating device and operating under predetermined conditions to eEect momentarily the energization of one or the other'of said magnets.

3. An electric circuit containing a switch for opening and closing said circuit, a translating device supplied by said circuit, a pair of magnets for operating the switch to open and close said circuit, an automatic regulating device controlled by the condition of the translating device and operating under predetermined conditions to close an auxiliary or shunt circuit through one or the other of said magnets, thereby energizing one or the other of said magnets and opening or closing the said main circuit as desired.

4. An electric circuit containing a switch for opening and closing said circuit, a translating' device supplied by said circuit, a pair of magnets for operating the switch to open and close said circuit, an automatic regulating device controlled by the condition of the translating device and operating under predetermined conditions to close momentarily an auxiliary or shunt circuit through one or the other of said magnets, thereby energizing momentarily one or the other of said magnets and opening or closing the said main circuit as desired.

5. An electric circuit containing a translating device and a switch for opening and closing' said circuit, a pair of magnets for respectively causing the opening and closing movements of said switch, an auxiliary or shunt circuit for each of said magnets, an automatic regulating device controlled by the condition of the translating device and operating under predetermined conditions to close one or the other of said auxiliary or shunt circuits and thereby open or close said main circuit as desired.

6. An electric circuit containing a translating device and a switch for opening and closing said circuit, a pair of magnets for respectively causing the opening and closing movements of said switch, an auxiliary or shunt circuit for each of said magnets, an automatic regulating device controlled by the condition of the translating device and operating under predetermined ,conditions to close momentarily one or the other of said auxiliary or shunt circuits and thereby open or close said main circuit as desired.

7. An electric circuit containing a translating device and a switch for opening and closing said circuit, said switch comprising a pivoted switch-arm and a pair of solenoid-magnets, the cores of which magnets are connected to the switch-arm at opposite sides of its pivot, a thermostat controlled by the caloric condition of the translating device and operating under predetermined caloric conditions to effect the energization of one or the other of said magnets and thus cause the opening or closing of the circuit as desired.

8. An electric circuit containing a translating device and a switch for opening and closing said circuit, said switch comprising a pivoted switch-arm and a pair of solenoid-magnets, the cores of which are connected to the switch-arm at opposite sides of its pivot, two auxiliary or shunt circuits, each containing one of said magnets, a thermostat controlled by the caloric condition of the translating' deviceand operating under predetermined caloric conditions to effect the closing of one or the other of said auxiliary or shunt circuits and thus cause the opening or closing' of the main circuit as desired.

9. An electric circuit containing an electric furnace and a switch for opening and closing said circuit, said switch comprising a pivoted switch-arm and a pair of solenoid-magnets, the cores of which magnets are connected to the switch-arm at opposite sides of its pivot, a thermostat controlled by the caloric condition of the electric furnace and operating under predetermined caloric conditions to `effect the energization of one or the other of said magnets and thus cause the opening' or closing of the circuit as desired.

10. An electric circuit containing an electric furnace and a switch for opening and closing said circuit, said switch comprising a pivoted switch-arm and a pair of solenoid-magnets, the cores of which are connected to the switcharm at opposite sides of its pivot, two auxiliary or shunt circuits, each containing one of said magnets, a thermostat controlled by the TOO -ITO

to this specification in the presence oi. two suhscribing wltucsses.

JAS. IA. AYER.

'Vitnesses:

ELIZABmH M. CONLIN, Doi-:A A. Picooloi.. 

